1. Field of the Invention
This invention relates to rotary valves for use with internal combustion engines. It relates further to means for cooling rotary valves and other rotary mechanisms. It relates still further to the lubrication of rotary valves. It also relates to rotary valves having a spherical shape or a shape which is similar such as an ovoid, obloid, ellipsoid, parabaloid, ball, globular and so forth. This group of shapes will be referred to herein as spheroidal.
2. Background of the Invention
Valves known to be suitable for internal combustion engines may be classified according to both their action, which may be either lifting or sliding, and their motion which may be classed either as oscillatory or continuous. The conventional poppet valve for example has lift action and its operation requires oscillatory motion. The sliding action valve however may be designed to operate either with oscillatory motion or with a continuous motion provided by rotation, the latter valves being classed as rotary.
During development of the combustion engine, inventors have sought a continuous motion to improve on the oscillatory poppet with its speed limitations, complexity, cost, and in some cases, noise. In the prior art, an estimated 2,000 patents may be found which relate to novel rotary valves for use on an IC engine. Of these, approximately 70 patents, including both U. S. and foreign, may be found which relate to spheroidal valves. The following have relevance to the invention herein.
Charles G. Wridgway, an Englishman, in U.S. Pat. No. 942,124 issued Dec. 7, 1909 fully describes application of a spheroidal valve to an IC engine. The ingenuity and limited claims of Wridgway's invention suggests that earlier art existed when he applied Dec 31, 1908. His use of a single valve rotor to valve two adjacent cylinders of an engine has considerable merit however and was apparently used in the cylindric valved Itala engines.
M. G. Chandler in U.S. Pat. No. 1,080,892 issued Dec. 9, 1913 describes a spherical rotary valve with a peripheral port and fixed sealing ring. It is not known whether Chandler's valve worked, as no split is shown or described in the circular seal used to seal combustion pressure against the sphere. If no split was used and thus no possibility for radial expansion of the ring under gas pressure, the valve seal would have leaked, probably making the engine inoperable. If Chandler did use a split seal, the rotary valve engine would probably have operated well for several minutes. Provision for cooling however appear to be insufficient. Therefore, if run at any appreciable power output, the valve rotor would have overheated. Chandler does not describe any necessity for specifically cooling the seal. His valve also appears to have contacted the casing over its entire surface which would have created problems.
Jan Zeeman in U.S. Pat. No. 1,868,301 issued Jul. 19, 1932 discusses the need to regain the explosive gas-mixture left in the valve chambers after the inlet (stroke) and a method for accomplishing it. No special control of the scavenging flow is described.
Jean-Claude Fayard in U.S. Pat. No. 4,606,309 issued Aug. 19, 1986 describes a method of scavenging wherein the inducted mixture is leaned out towards the end of the inlet stroke. Fayard's method and end result both differ from the scavenging described herein.
The prior art regarding gas sealing indicates that other inventors consider the seal situation workable but not perfected. The variety of recent patents issued on seals for a rotary valve indicate that other inventors have not finalized a workable seal arrangement.
Metered lubrication is a straight forward mechanical engineering problem. However known metering methods that allow control of oil flow are complicated and expensive. No prior art could be found re a metering system as described herein.
Cooling methods were found for a rotary valve such as the following:
1) Flowing coolant through a hollow rotor shaft and through the rotor, PA1 2) Flooding the rotor surface with coolant and re-collecting the coolant, PA1 3) Spraying water through the hot rotor port, PA1 4) Conducting heat out to a pad or a portion of the rotor casing held tightly against the rotor, the pad or casing portion being cooled.
James I. Thompson in U.S. Pat. No. 880,601 issued Mar. 3, 1908 for example clearly describes a frusto-conical valve for the combustion chamber of a gas engine and teaches a method for flowing water or air coolant through the valve. Other patents describe internal coolant flow through rotary cylindric and spheric valves. Due to the need for at least one rotary seal in the valve shaft for liquid coolant, these cooling methods cannot achieve the high reliability and low cost of contemporary poppet valve art.
E. Ballou in U.S. Pat. No. 1,018,386 issued Feb. 20, 1912 describes a rotary valve having double curvature and includes ovoids and ellipsoids. Ballou does not elaborate and gives no specific preferred shapes, no reasons for using such shapes in lieu of spherical shapes, and no suggestions for engineering such shapes into a valve. No detail was given regarding the amount of double curvature desired and very little was said as to the improvement obtained on valve operation by its use. Ballou's non-spherical shapes appeared to be merely concepts, with very little taught about their benefit or method of use.
J. J. Genet in French Patent # 970,264 issued Jan. 2, 1951 discusses ellipsoidal and ovoidal shapes for a rotary valve rotor. However, he does not describe how such shapes should be designed and used in a valve nor what purpose they serve, and he provides no drawings. Genet's non-spherical shapes do not appear to be sufficiently well taught for someone skilled in engine art to understand their purpose or to understand how to apply them to an engine and obtain a benefit over the use of a spherical valve, since even the spherical shape is almost unknown except in the world's patent files.
D. F. Browne in U.S. Pat. No. 4,821,692 issued Apr. 18, 1989 describes a spherical valve rotor rotatable and offsetable in a spheroidal casing to obtain better sealing. Browne's invention was determined to be geometrically different from my invention described herein.
Albert E. Moorhead in U.S. Pat. No. 1,218,296 issued Mar. 6, 1917 describes a spherical valve rotor using a through port insulated from the surface by a filling of asbestos or other insulating material. The insulated port alone is therefore old art. The "through port" valve of Moorhead's has approximately three times the surface area of a peripheral port and would collect three times as much heat from the exhaust. It would be difficult to keep such a valve properly cool.
F. A. Wyczalek et al in U.S. Pat. No. 3,965,681 issued Jun. 29, 1976 describes a metal liner in an engine exhaust port, the purpose being to carry the hot exhaust gas more efficiently to an exhaust turbine. This is in effect an insulating liner in the port with no attempt to conduct heat downstream and away from the cylinder head.
Some two-stroke engines are now being manufactured with auxiliary rotary inlet or exhaust valves placed in series with piston valved ports on the cylinder walls. These valves aid in timing gas flows in a two-stroke engine and in such application, they withstand only a few pounds per square inch, their designs being inadequate for the thousand pounds per square inch of a combustion chamber.
No prior art was found describing the art of cooling a rotary valve as is taught herein. No mention was found regarding the control or metering of oil to a rotary valve.